The present invention relates to a conical roller bearing in which an inner ring, conical rollers and a cage are fitted together into an assembly.
For example, the assembling of constituent parts into a conical roller bearing 100 shown in FIG. 4 (Patent Literature 1) is carried out as follows: a plurality of conical rollers 140 are aligned on an inner-ring-side raceway surface 121 of an inner ring 120, a cage 130 is fitted from an outer circumferential side of the plurality of conical rollers 140 which are arranged into a ring shape, a first annular portion 131 at a small-diameter side of the cage 130 is crimped radially inwards so that the conical rollers 140 are made difficult to be disengaged from the cage 130, and an outer ring 110 is fitted from the outer circumferential side of the plurality of conical rollers 140 which are arranged into the ring shape.
The inner ring 120, the conical rollers 140 and the cage 130 are prevented from being disassembled by crimping the annular portion 131 at the small-diameter side of the cage 130 radially inwards, whereby those constituent parts are fitted together into an assembly. By fitting them together into the assembly, the inner ring 120, the conical rollers 140 and the cage 130 can be transported as an assembly without the outer ring 110.
In the event that the first annular portion 131 at the small-diameter side of the cage 130 is crimped radially inwards too much, the conical rollers 140 may be brought into contact with pockets 134 to thereby prevent the smooth rolling of the conical rollers 140.
As a countermeasure against the aforesaid problem, there is provided a conical roller bearing 200 shown in FIG. 3 (Patent Literature 2). The assembling of constituent parts into the conical roller bearing 200 is carried out as follows: a plurality of conical rollers 240 are aligned on an inner-ring-side raceway surface 221 of an inner ring 220, a cage 230 is fitted from an outer circumferential side of the plurality of conical rollers 240 which are arranged into a ring shape, an erected portion 231 at a small-diameter side of the cage 230 is deformed so as to ride over a small-diameter end portion 223, a radially inner side of the erected portion 231 is brought into engagement with an annular groove 223a in an axial direction of the inner ring 220, and an outer ring 210 is fitted from the outer circumferential side of the plurality of conical rollers 240 which are arranged into the ring configuration.
In this conical roller bearing 200, the inner ring 220, the conical rollers 240 and the cage 230 are prevented from being disassembled by bringing the erected portion 231 into engagement with the annular groove 223a in place of crimping the cage 230 radially inwards, whereby the inner ring 220, the conical rollers 240 and the cage 230 are fitted together into an assembly. The inner ring 220, the conical rollers 240 and the cage 230 can be transported as an assembly without the outer ring 210 by those constituent parts being fitted together into the assembly.
In order to allow a radially inward distal end of the erected portion 231 to ride over the small-diameter end portion 223, the cage 230 needs to be formed from a resin so as to allow the erected portion 231 to be bent largely. Because of this, there is imposed a limitation on the cage 230 that the cage 230 has to be formed from a resin, leading to fears that the erected portion 231 is damaged at a root thereof.
[Patent Literature 1] JP-B-4009047
[Patent Literature 2] JP-Y-58-50094